Question

The average of three test scores of the first two scores are 77 and 89

Answer 1

A = (166+s)/3

Explanation:

Average test-score:

Sum of all scores divided by the number of tests.

In this question:

First two tests: 77 and 89.

Third test: s

Number of tests: 3

Average:

Finding the sum: 77 + 89 + s = 166 + s

The average is:

A = (166+s)/3